Alkylene oxides may be prepared by reaction of an alkylene and hydrogen peroxide, hydroperoxide, or oxygen and hydrogen. Generally, these reactions are carried out in a liquid solvent, e.g., an alkyl alcohol and water, and in the presence of a solid, metal containing catalyst. However, the use of one or more alkyl alcohols as a solvent can be problematic in that the separation of the same from the desired alkylene oxide requires energy intensive distillation operations comprising a large number of trays, and operated at high reflux rates. In order to reduce the economic burden imposed by the use of the alkyl alcohol, a majority, if not all, of the alkyl alcohol may typically be recycled once separated from the alkylene oxide.
In order to further reduce this burden, alternative separation techniques have been proposed, many involving the use of extractive distillation. However, the proposed solutions often introduce additional problems. For example, the addition of an extraction solvent increases the size requirement of the distillation column used to remove the alkyl alcohol due to the added volume of the extraction solvent.
Desirably, methods for the production of alkylene oxide would be developed that provide for the separation of an alkyl alcohol from an alkylene oxide with reduced difficulty and/or economic burden as compared to conventional or extractive distillation methods.